If duplicate - show list and allow selection

[Dana G]

We have a contacts table with several thousand contacts. Inevitably there are going to be instances where two people have the same name but work for different companies. I would like to know if there is a way to have a window pop up that says, for example..."There is more than one John Smith in our system. Please select which person you would like to use." Somehow I would like to have a way for the person to select from a list of those people and have the individuals contact info fill into the correct fields.